1. Technical Field of the Invention
The present invention relates to an information transmission apparatus that transmits information, and in particular, to an information transmission apparatus that transmits a plurality of pieces of data associated with a motor control apparatus.
2. Related Art
As an information transmission apparatus that transmits information, for example, JP-A-2009-171312 discloses an on-board information transmission apparatus.
The on-board information transmission apparatus is an apparatus for transmitting temperature information detected by a temperature sense diode. The apparatus includes a frequency modulation circuit, a photo coupler, and a microcomputer. In the apparatus, the temperature sense diode senses temperature and outputs the corresponding voltage. The frequency modulation circuit produces frequency-modulated signals associated with the outputted voltage. The microcomputer receives the frequency-modulated signal via the photo coupler and demodulates them, thereby obtaining the temperature information sensed by the temperature sense diode.
In the case where a plurality of pieces of temperature information are transmitted, the above on-board information transmission apparatus is needed to be provided with the frequency modulation circuit and the photo coupler for each piece of temperature information to be transmitted. Therefore, an issue occurs in that the circuit configuration becomes complicated and an increase in cost is caused.